I want to show sum by all year and doesn't change on user selection
Sum({1<Year={$(=Year)}>}Sales)
use Set Analysis
Sum({1<Year={'2018'}>} Amount)
On Irrespective of Selection:
=Sum({1<Year = {'2018'}>}Sales)
On excluding current selections:
=Sum({1-$<Year = {'2018'}>}Sales)
on all years:
=Sum({<Year = >}Sales).
Sum({1<Year={$(=Year)}>}Sales)